Selected Publications

Boursi B, Stemmer A, Chapin WJ, Shacham-Shmueli E, Kopetz S, Andre T, Overman MJ, Pietrantonio F, Margalit O. : Durable responses to immunotherapy in dMMR/MSI-H metastatic colorectal cancer patients with poor performance status. American Society of Clinical Oncology Annual Gastrointestinal Meeting, San Francisco, CA. Jan 2026 Notes: "Poster Presentation"

Kim RD, Saeed A, Chapin WJ, Kim K, Iyer R, Martin II RC, Grothey A, Gadde S, Feun LG, Gabayan A, Saenger YM, Abdelrahim M, Govada N, Xie B, Cho M, Burgoyne A.: A multicenter, open-label study of RP2 oncolytic immunotherapy expressing anti–CTLA-4 in combination with second-line atezolizumab plus bevacizumab in advanced hepatocellular carcinoma (HCC) or in combination with first-line durvalumab in advanced biliary tract cancer (BTC). American Society of Clinical Oncology Annual Gastrointestinal Meeting, San Francisco, CA. Jan 2026 Notes: "Poster Presentation"

Boursi B, Kolkey ZL, Reiss KA, O'Hara MH, Chapin WJ. : Comparative effectiveness of oxaliplatin or irinotecan rechallenge vs standard third-line therapies in patients with metastatic colorectal cancer. American Society of Clinical Oncology Annual Gastrointestinal Meeting, San Francisco, CA. Jan 2026 Notes: "Poster Presentation"

Lin JK, Niu J, Giordano SH, Li P, Snyder RA, Liao K, Li M, Aparicio A, Chapin W, Zhang J, Xiang J, Perera N, Pain D, Guerra CE, Doshi JA.: Racial and Ethnic Disparities Along the Treatment Cascade Among Medicare Fee-for-Service Beneficiaries With Metastatic Breast, Colorectal, Lung, and Prostate Cancers. J Clin Oncol Aug 2025.

Swami N, Hwang WT, Mamtani R, O'Hara MH, Chapin WJ.: Second-Line Treatment Strategies for Right-Sided, RAS/RAF Wild-Type Colorectal Cancer. JAMA Netw Open 8: e2515087, Jun 2025.

Swami N, Hwang WT, O’Hara MH, Chapin WJ. : Real-world evaluation of a “hyperselection” predictive biomarker for anti-EGFR therapy benefit in patients with RAS/RAF wild-type, MMRp/MSS mCRC. J Clin Oncol 43(16), May 2025 Notes: Swami N, Hwang WT, O’Hara MH, Chapin WJ. Real-world evaluation of a “hyperselection” predictive biomarker for anti-EGFR therapy benefit in patients with RAS/RAF wild-type, MMRp/MSS mCRC. J Clin Oncol. 2025;43(16_suppl):e15591-e15591. doi:10.1200/JCO.2025.43.16_suppl.e15591.

Nishwant Swami , Wei-Ting Hwang , Ronac Mamtani , Mark O'Hara , William Chapin: Real-world survival comparison of second-line treatment strategies for patients with RAS/RAF wild-type, right-sided metastatic colorectal cancer. Journal of Clinical Oncology 43(4_suppl): 73, Jan 2025.

Margalit O, Stemmer A, Chapin WJ, Schacham-Shmueli E, Kopetz S, Andre T, Overman MJ, Pietrantonio F, Boursi B: Duration of Immunotherapy in dMMR/MSI-H Metastatic Colorectal Cancer Patients. European Journal of Cancer 212: 114336, Nov 2024 Notes: doi: 10.1016/j.ejca.2024.114336.

Chapin WJ, Hwang W, Mamtani R, O’Hara MH: Real-world uptake and effectiveness of triplet versus doublet chemotherapy with bevacizumab in patients with metastatic colorectal cancer in the United States. ESMO Gastrointestinal Oncology 5: 100087, Sep 2024.

Chapin WJ, Hwang W, Mamtani R, O’Hara MH: Low- vs High-Dose 5-FU in Triplet Chemotherapy Plus Bevacizumab for Patients With Colorectal Cancer. JAMA Netw Open 7(7): e2424855, July 2024.